1. Field of the Invention
The present invention relates to an optical module using a bared cladding of an optical fiber, where a semiconductor optical device is mounted thereon.
2. Related Prior Art
A silicon substrate having a V-groove is typically used for an optical module that an optical fiber and a semiconductor laser diode are optically coupled with a butt joint. Japanese patent published as 2000-171668 has disclosed such optical module having the silicon substrate with the V-groove. The optical fiber embedded within the V-groove is butted against a wall of the groove and is coupled with the laser diode mounted on a primary surface of the silicon substrate.
In the case that the silicon substrate is used to optically couple the laser diode with the optical fiber, the laser diode and the optical fiber must be aligned with the silicon substrate. The optical fiber is easily aligned with the substrate by embedding the fiber into the V-groove. However, the alignment of the laser diode with the substrate is not as simple as that of the optical fiber. Alignment mark is formed by the etching of the substrate, or is deposited with a patterned metal film on the substrate. The laser diode is aligned with the substrate by using thus formed alignment mark.
However, such configuration using the V-groove or the alignment mark leads the scattering in the optical coupling efficiency by two step alignment, namely, between the laser diode and the substrate and between the optical fiber and the substrate.